Work blasting machine



ug. 2, 1949. 'w. l. GLADFELTER WORK BLASTING MACHINE 5 Sheets-Sheet 1Filed May 20, 1948 gmc/who@ W. l. GLADFELTER WORK BLASTING MACHINE Aug.2, 1949.

3 Sheets-Sheet 2 Filed May 20, 1948 IWC/H1105 775.21 GMOFELTE'@ Aug. 2,1949.

w. l. GLADFELTER 2,478,156

WORK BLASTING MACHINE Filed May 20, 1948 3 Sheets-Sheet 5 Patented ug.2, 1949 UNITED STATES Q'fFFICE.

WORK BLASTING MACHINE Wltie I. Gladfelter, Hagerstown, Md., assignerr`to Pangborn Corporation; llagerstown,v Md., a corporation of MarylandApplication May 20, 1948-, Serial No. 28,227

(CI S14-15) which combinesl simplicity, great strengthand great;flexibility with economy in cost and in operation, without' sacrifice ofefficiency.

Other' objects and-.advantages vof the invention and ofparticularifeatures thereof will beappar; ent Afrom'thefollc'nving description vofa preferred embodiment of the zsame;

With the foregoing general objects in mind, the-invention comprises,among other things,` van improved blasting machine: which includes ahousing enclosing a rotaryfwork suporting table and means forblastingworkl supported thereby, the housing being openable with`respect to both its' vertical side'l and contiguousportionsv of itsroof -or topttvall,L so that heavyV work-may befcarrieda to and lremoved directlyvfrom -the central portions of the table by af crane orthelikej. More` particularly thisportion ofthe invention com prises.Y ahousingprL casing having.` the blasting means and table. completelyenclosedrtherein and witha portion ofthe casing-provded-with piesegment`.doorsembracing. contiguous yportions of the-.side Walls and .segmental.sections-.of theroof, and arranged l so thatr in .opened position theyuncover over half the area ofthe. table. The invention. also comprisesa. simple, efficacious.. machine in which the tableis supported `insuch.. manner that. its weight may be distributed. directlytotheunderlying floor so'that n0 pit .is

required for its installation. In its preferred form; the invention alsocomprises. a new and. unique' arrangement for Ventilating such a table;special provisions for cutting off the blastingop'eration'if thedoorsareopened; advan'- tageous means for securing and sealing of the doors;`Iand an arrangement for allowing'the biastant "and detritus separating"elements to opcrate" during the unloading and loading. of the' machine,as welIas during the blastingopera tion,'..thereby' reducing the sizeand cost ofith'e separator 'and the sizeand' costof the 'dust"co1'lector associatedv with the.machine;aswell` as" other novel featuresand". combinations.' herein; after pointed `out `and claimed..

In the accompanying drawings 'showing afpree f erred emboclinflentl of'`the invention`vr Fig. l'is a topplan View ofthe machine; Fig. 2 is aside elevationthereofj Fig. 3 -is` an enlarged detail sectionthrough theair inlet taken on line 3-3`of Fig. lasindicated; Fig. 4 is an enlarged"detailof'thedoorrbottom' baffling and sealing means;

Fig. 5 is an enlarged detail ofthe' tableand'l scraper support and drivemeans:

In the form shown in the drawings the blasting machine comprises a,perforated rotatableI worktable Ill, preferably carrying a rubberY linervII perforated in coincidence. with" the tableperr forations, andwhichis mounted' for rotation'k aboutv a verticalaXis I2 'onisuitablebearings' exL empliedat I 3`,V Fig. 5.

As. is best shown in Fig. 2"the table support is carried .by transversechannel orother structural' lecting pan I8 andserving to push thecollected' grit `or shot and detritus therefrom into an abra'-sivecollctinglhopper I9" which mayfb'e provided nails or wires, etc.,before the'blastant'an'd detri;

tusfare delivered tothe. boot of the elevating' bucket 'conveyor2I-(Figs..1'and'2).

The .elevator conveyor. extends upwardly` from the rear of the machine,preferably inside the housing thereof, vto a, positionabove the blastantsupply hopper 22, and isdrivenv by a motor 23 'as through the belt drive2'4.

The material'raised by the elevator 2I is delivered to a separator25'which may be of'relatively simple construction, wherein the detritus,

andfthe fines resultingfrom'breakup of the shot' or gritdue to theblasting impact, are inconsiderablpartseparated from the reusableblastant and delivered through a. .discharge pipe or dis- In this way,with no` with a screen plate 2li for screening outlarge' E chargeconduit 26 to a suitable disposal receptacle 21, Fig. 1. The reusablegrit delivered from the separator 25 is returned to the supply hopper 22preferably through a screen 28.

As is shown near the bottom of Fig. 2, the elevator shaft or casingpreferably communicates with the blasting chamber 29, and a baffledopening 39 may provide such communication.

In the illustrative embodiment the elevator shaft is employed as the airoff-take conduit from the blasting chamber so that dust thrown uptherein may be drawn off through the louvers 39 and delivered from theair outlet 3| to a suitable suction fan and dust-separating apparatus.

As dust is also removed in the separator 25 a further dust conduit 32 isprovided which, as

shown in Fig. l, communicates with the discharge I line leading from theoutlet 3|,

In the form shown, the blasting chamber 29 and the lower end of theelevator 2| are enclosed by a housing 33. This housing has a generallysemi-oval front section embracing more than a dianietrical half of thetable I9, the top and side walls of which consist of contiguous doorsopenable to expose the same so that the hook of a crane may be broughtdirectly above the center of the table to place and remove therefromlarge and heavy castings and the like.

In the preferred form shown the openable sections constitute twocontiguous arcuate doors 3d each embracing more than a quadrant of thetable and hinged laterally' `to the remainder of the casing at 35.

Each door St in the form shown is of pie-segment form and comprises asection' of side wall embracing more than a quadrant of the table and acorresponding section of top wall of the housing. The abutting edges ofthe two doors 3Q, and the jamb edges of the door ways and of the doorsabutting thereagainst, are similarly flanged as indicated at 36 and 31;and one of each pair of flanged edges is provided with a suitablesealing means or packing such as the rubber or like gasket shown at 33,Fig. Il. No external flange corresponding to flange 36 is required atthe top edge of the door as this edge is rigidied by the pie-segmentshaped roofed portion.

Means is provided for securing the two doors in closed abuttingrelation. In the preferred form shown, this means comprises a toggleclamp or latch 39, Fig. 1, having main arms pivoted to one of the doorsat ill and supporting a shaft 4| to which are secured toggle dogs l2 andan operating handle 33. The toggle dogs 42 enter keepers icl and, asthese dogs and the handle 43 are swung about the shaft 4|, draw the twodoors closely together, compressing the packings associated therewith,and` passing by dead-center so that the latch remains in closed positionuntil a positive pull on the handle d3 releases the toggle action.

As is best shown in Figs. 2, 4 and 5, the table I5 has a hanged edge 45which extends to or above the height of the lower casing portion 46, andthe lower casing portion t is marginally reenforced at l1 and providedwith a hanging skirt of rubber or the like i8 for protecting itl fromflying blasting particles. Liners 1l9 are also provided for the innerwalls of the blasting chamber 29 which are exposed to wild flyingabrasive during the blasting operation. As shown in Fig.

4, the liners for the door sections 3ft are in the` form of hangingsheets of rubber, and the lower' edges thereof are held away from thedoor by' baffle plates or brackets 55 which project from the 4 doorwalls 34 and over the lower portions of the' housing @l5-G8 and areprovided with a sealing ring 5| engageable therewith.

As is shown in Figs. 1 and 2 baffled air inlets 52 are provided in theroof of housing 33, and in the preferred form are carried by the roofsections of the door elements 3ft. As indicated in Fig. 3, these inletspreferably comprise a hoodshaped baille 53 within the outer casing 52and overlying the air inlet tube 5d, and the lower end of the casing 52may have outlet orifices between spacer elements 55 overlying baffles 56to return to the blasting chamber any particles which may pass into theair inlet chamber.

Means for rotating the table is provided, preferably in the form of afriction drive roll 51 carried by a depending shaft 58 which is drivenby motor 59 through suitable reduction gearing 56. The shaft 58 may beprovided with various auxiliary elements, omitted for clarity, such as auniversal joint, spring means or the like for supported in a housing 62,herein carried in the top wall of the housing 33, the projector 6| beingoriented to direct its fanlike blast stream diagonally across the tableas shown at G3, Fig. l,

vand against work pieces supported thereon.

In the form shown, the wheel is rotated in a direction to deliver theblastant in an undershot direction as indicated at G4, Fig. 2, so thatit blasts both the top and side portions of the l work, and the blaststream is directed diagonally of the blasting chamber so as to misalignit with the abutting jambs of the door members 34. Thus the principalquantity of wild flying abrasive strikes one of the door sections in theregion 65, which region is preferably provided with a double layer ofthe rubber lining members 49 (Fig. 4).

In the illustrative embodiment the blast wheel 6| is driven by a motor66 through a belt drive or the like 61, and the blasting particles arefed to the blast wheel from the supply 22 through a conduit E8'(Fig. 2),which is provided with a suitable abrasive flow controlling valve 69,best shown in Fig. 1. As is usual, the abrasive feed line 68 delivers tothe wheels 6| in a generally axial direction and on the opposite side ofthe housing 62 from the drive shaft 10 (Fig. 1).

As is shown in Figs. 1 and 2, the hopper bottom 1I of the supply 22 ispreferably provided with a second feed delivery valve 12 which controlsthe delivery of abrasive from the supply to a by-pass conduit 13. ThisAconduit in the arrangement shown descends through the rear portion ofthe blasting chamber, is formed of rubber hose, and discharges directlyto the spent abrasive hopper I9 and thus by way of the elevator 2| tothe separator 25.

The valve elements B9 and 12, as shown, are

preferably ganged and controlled by a common.

actuator 14 shown as a shaft rotatable by a crank and control handle 15,to at least two abrasive feeding positions. In the first or wheelfeeding position, abrasive is fed from the supply 22 to the wheel 6| forprojection thereby. In the second, or by-pass positions, the abrasivesupply to the wheel is cut oif and the abrasive is fed from the supply2| through the by-pass 13.

garenne;

Preferably oneorfthe other ofthese .feeds is iemaployed` whenever the.machineis-V in operatiom.

Byffthis-iprovisienthe abrzat-sivev-from` the supply 22f^-isicontinuouslyy recirculated through the .separa-toriaduringythoseeintervalsf-of time when the dgors are open forinspectionnof thework,l

turning thereof to expcseunblasted areas, and loading and unipatilingof.' the table. Thus the separating of detritus from the' abrasivecontinueathroughcut the period of blasting f and'iaflso throughout theintervening non-.blastingrperiodsl- By virtue offthisfpravision thesize-ofthe supply hopper 22,'may be reduced, the necessary capacity ofthe separator 25 minimized, and because of the reducedlcapaei-tyofthe-separator, theyolume of fdust delivered to thedustcollectorperunit of ftime i isf reduced enabling use of a smallerand less;-expensive dust collector;

Means is preferably provided operative to terminate the blastingoperation by cutting off the supply of abrasive to the wheel, or byeffecting quick stoppage of the Wheel, on any initial movement of thedoors 34 toward opened position. As shown in Figs. 1 and 2, this meanscomprises a stop switch 16 actuated by an abutment 11 carried by one ofthe doors 34 and adapted to cut off the supply of abrasive to the wheeland/or stop the wheel by any of the various arrangements known to theart. When a 6-foot table is employed a suitable speed of rotation of thetable is about 21/2-R. P. M. and the chamber may receive pieces as largeas three feet high and six feet wide. As the table in effect issupported directly on the floor with the intervention of load spreadingmembers, an extremely heavy load of castings, which may approximate vethousand pounds, may be carried by it on normal foundry floors withoutspecial strengthening provisions.

In use of the machine the operator places the work on the table, clampsthe doors shut and turns on the wheel and table drive. The operator maythen take time to prepare the next batch of work for loading, which hecould not do if he had to control the blasting in a blast room.Moreover, the table rotates and the blasting occurs entirely within theenclosure formed by the stationary and swinging door portions of thehousing. Thus harming of the operator by escape of abrasive from thefront of the machine is eliminated, and the normal hazards of anordinary blast room, where the operator comes into contact withrebounding abrasive, are avoided. After blasting for a certain length oftime, the operator shuts off the wheel, opens the doors and examines thework, takes the pieces off that are thoroughly cleaned, and turns thepieces over that are not cleaned on all sides.

From the foregoing it will be apparent that the present inventionprovides an economical and versatile machine, combining the advantagesof a blasting room and blasting table and including features cooperatingfor economy in its initial cost and cost of operation.

It is to be understood that the features of the invention may beembodied in specific forms other than those illustrated withoutdeparting from the principles or essential characteristics thereof. Theembodiments shown are therefore to be considered as illustrative and notrestrictive, the scope of the invention being dened by the appendedclaims. All modifications and changes which come within the meaning andrange of equivalency of the claims are therefore intended to be includedtherein.

Iffclaimas'myfinvention:

1; In a .blastingsmachina `and in. combmation; a worlcesupportin-gAtable; a housingl enclosing`A as.

chamberaaboutfandiabove: said table; saidfhmfising.l

,- having door means openable to .eXpose-saidtable' toafacilitaterloading.. and .unloadinga` thereof, a

through said: housing adjacent said.' table, and communicating with saidhousing; means; for: sucking: airffromnsaid lhousing:through said elieavator, and bailled ain inlet means carri'edibyrthe,

top; of'Jsaid4 housing for admitting -air thereto.

2.- In .a blasting` machine, and in combination, a'. workesupportingtable, a housing enclosing-'a1v chamber aboutandfabove saidtable,said'houseV ing-having door means openable-to exposesaidf table tofacilitate loading and unloading thereof, a blast-stream projectorpositioned to direct its blast stream against work pieces supported onsaid table, and means actuated by the initial opening movement of saiddoor means for interrupting operation of said blast projector.

3. In a blasting machine, and in combination, a housing surrounding ablasting chamber, work supporting means in said chamber, said housinghaving access means openable to enable work to be placed on and removedfrom said work supporting means, means for projecting blasting particlesagainst work supported on said work supporting means, a blastingparticle supply, means for separating blasting particles from detritusfreed by the blasting operation and returning the particles to saidsupply, a conduit for feeding blasting particles to said projector, aby-pass for recirculating blasting particles through said separatingmeans, and two path valve means associated with said conduit and saidby-pass for feeding blasting particles from said supply to said conduitin one feeding position thereof and from said supply to said by-pass inthe other feeding position thereof.

4. In a blasting machine, and in combination, means defining a blastingchamber in which work is intermittently blasted, means for projectingblasting particles into said chamber, a blasting particle supply, meansfor collecting spent particles and detritus from said chamber, forseparating detritus from the collected particles, and for returning theparticles to said supply, a conduit for feeding blasting particles tosaid projector, a by-pas-s for feeding blasting particles to saidseparating means, and two path valve means associated with said conduitand said by-pass for feeding blasting particles from said supply to saidconduit in one feeding position thereof, and from said supply to saidby-pass in the other feeding position thereof.

5. In a blasting machine, and in combination, a rotary table, a housingenclosing a chamber about and above said table, said housing having agenerally semi-oval top wall and side wall portion embracing more than adiametric half of said table, the side and top walls of said semiovalportion being in the form `of swinging doors openable to afford verticaland lateral access to more than a diametric half of the table.

6. In a blasting machine and in combination, a rotary table, a housingenclosing a chamber about and above said table, said housing having twoabutting pie-segment doors each comprising a part of the side wall and apart of the top wall of the housing, said doors together embracing morethan a diametric half of the table, and

2,478, 1 se f 8. A combination according to claim 7, said 10 doorscomprising sealing means between their abutting edges, and having meansfor clamping together their abutting lateral edges.

9. A blasting machine comprising a cabinet, a rotative table mountedentirely within the cabinet, a blasting means carried by said cabinetand discharging across said table, the side and top Walls of saidcabinet comprising swingable doors Whichcan open widely enough tofacilitate handling of castings being placed on or removed from saidtable, said doors comprising a portion of the top of said cabinetextending from the side thereof to a position overlying the centralportions of the table.

WILTIE I. GLADFELTER.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,214,641 Billings Feb. 6, 19172,258,634 Turnbull Oct. 14, 1941 2,414,038 Gossard Jan. '7, 19472,451,049 Tell Oct. 12, 1948

